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OneWeb satellite constellation coverage animation

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Admin1
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Sep 3rd, 2021 at 8:39am  
The Oneweb satellite constellation is not yet complete so whole world coverage is not yet possible.
The satellites are at 1200km height.

...

This picture above is a snapshot of an animation. 3 Sept 2021,  showing the coverages below each OneWeb satellite.  It is an unofficial plot based on published satellite TLEs so may be wrong regarding which satellites are active.

Best regards, Eric
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Admin1
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Reply #1 - Dec 7th, 2021 at 4:32pm  
The circular coverages on the image above look wrong to me.  I think that each OneWeb satellite has 16 beams, arrayed north-south of each other, with each above/below the next, so the coverage of each satellite is essentially a square.  Each of the 16 beams is highly elongated east-west and narrow north-south.

Does anyone agree with this below ?

Ku band customer beams (down 12.75-13.25, up 14-14.5 GHz).
16 Ku band beams, wide east-west, narrow north-south.
Each satellite covers a square area of 48 deg x 48 deg,
Ku band antennas: each comprising a single row of 32 rx/tx patches. Length 1m.
Coverage Beamwidth (-3dB) = 48 deg x 3 deg
Area = 113 sq deg.   Equiv circ = 6 deg radius.

Gain = +24.3 dBi beam centre      +21.3 dBi beam edge.

Uplink G/T = 24.3 - 10log(325) = -1 dB/K (at beam centre)
Uplink G/T = 21.3 - 10log(325) = -4 dB/K (at -3dB beam edge)


* calculation revised 6 Jan 2022. Note sure what figures to use for antenna efficiency or uplink noise temperature. For time being I am assuming all patches are the same (~100% eff) and earth + LNA = 325 deg.
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« Last Edit: Jan 6th, 2022 at 6:22pm by Admin1 »  
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